The Long Watch

A medium SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

medium

Seniority

mid

Problem

We're auditing our release cadence, where each successful production deploy of a service stays live until the next successful production deploy of that same service replaces it. The environment and status labels were recorded with inconsistent casing over the years, so match them case-insensitively. For every release that was eventually replaced, report the service, the version, and how many calendar days it stayed live, longest-lived first; when two releases held for the same number of days, list them alphabetically by service and then the earlier deploy first.

Summary

Every release holds until the next one relieves it. Find the ones that held longest.

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